Patent GB-154989-A (GB)
Title: Improved method and means of feeding sheets
IPC: B65H1/22
Filed: 1919-09-04
Abstract: 154,989. Reddie, L. N., (King, H. K.). Sept. 4, 1919. Tripping, throw-out, and like arrangements.- A device for feeding sheets of the kind in which the sheets are placed in a. feathered condition on an upper feedboard and are forwarded by banking devices to a lower feedboard on which they are separated by rising and falling combing-rollers is constructed so that the advancing edges of the sheets passing between the drop and feed rollers actuate a feeler mechanism, which controls pneumatically the rising and falling of the combing- rolls and also the operation of the banking devices, and in addition also pneumatically controls a holding-down device which acts on the rear ed'ge of the top sheet. The devices for raising the combing-rolls and the rear holding-down device are so constructed that their lift is independent of the thickness of the sheets. As shown, the sheets are advanced from an upper table 64, Fig. 2, by tapes 65, over a roller 66 with which co-operates tapes 69 and are fed in feathered condition over a lower feed table 71 by tapes 76, Fig. 5, driven from a pulley on a shaft 78 which at the commencement is operated by a handle 70. When the sheets extend past the combing-rolls 50, the automatic feed is commenced, the rolls 50 acting to comb out the top sheet and remain in action until the sheet acts on a feeler 27, Fig. 5, arranged between a feed roller 29 with which cooperates a drup feed roller (not shown). The feeler is thus raised out of a groove 28 in roller 29 and acts to permit a. catch 30 to release a support 31 which normally holds the spindle 32 of a piston valve in a raised position. The fall of the spindle causes a compressed air supply to be connected to a chamber 25, Fig. 2, containing a diaphragm which raises the combing-rollers out of action as soon as the compressed air acts on the diaphragm. While the combing-rollers are out of action a pneumatically-operated clutch which drives the shaft 78 of the tape drum is connected to a suction device by the piston valve described, and the bank feed is thus stopped simultaneously with the combing devices. After the sheet has passed the drop rollers, the feeler mechanism is re-set and the valve spindle 32 raised to its normal position by a spring-controlled lever 34 when its roller 37 enters a recess 36 in a cam 35. This connects the chamber 25 to exhaust and thus allows the combing-rollers to move into operative position, and also the valve then connects the air supply to a chamber which throws in the pneumatic clutch on the shaft 78, and the valve also connects the air supply to a chamber 119, Fig. 2, containing a diaphragm which raises a holding- down device 106 which normally acts in the rear of the top sheet. The combing-rolls 50 are mounted so that the pressure they exert on the sheets can be changed during the working operation, and they are mounted so as to be capable of resting on piles of different thickness and yet be tripped to the required extent independently of this thickness. The rolls 50 are carried by freely mounted frames 49 and normally rest by gravity on the sheets. This gravity pressure may be supplemented or relieved to a certain extent by means of a lever arm 47 on a shaft 45 and link 48. The shaft 45 is fitted with an arm on which a screw 43 is mounted, and a nut 42 adjustable along this arm permits the tension of a spring 40 to exert an adjustable pressure on the shaft 45 which may tend to move the arm 47 to supplement the action of gravity on the combing-rolls, or vice versa, according to which side of the axis of the shaft 45 the spring acts. To accommodate the rolls 50 to piles of different thickness the shaft 45 is fitted with a segmental plate 53, Fig. 3a, which normally can pass freely through a slot 58 in a plate 54 which is normally held by a spring 57 in the position shown in Fig. 3<a>. The shaft 45 is operated to raise the rolls out of combing action by a pneumatically-operated plunger rod 61 which, when depressed. first pivots the plate 54 about a fixed lug 56 so as to grip the plate 53, and then the plate 53 moves with the plate 54 and the rolls are raised the required distance. The shaft may be held in its raised position by an automatic catch released when desired by a hand-lever. To control the extent of movement given to the bank-feeding tapes, the pneumatically-operated clutch which drives the shaft 78 comprises a freely-mounted member 81, Fig. 5, which is oscillated from a cam 90 acting on a roller 93 on a frame 94 pivoted at 91. The frame 94 transmits an adjustable motion to a connection rod 92 connected by a universal joint to the member 81, the adjustment being obtained by shifting the position of a block 98, to which the rod 92 is swivelled, by means of a screw 96.